Apparatus for controlling the volume of air and the distribution of blood in the body



INVENTOR REUBEN FLANAGAN GRAY BY C N .El

May 14, 1963 R. FL GRAY 3,089,482

APPARATUS FOR CONTROLLING THE VOLUME OF AIR 4 ANDl THE DISTRIBUTION OF BLOOD IN THE BODY F'lled May 28,- 1959 3 Sheets-Sheet 2 I een 94 Kee a9 Kean 9 TV x31 Kee 31 I'/ 19 16 FKaab ,ji OXYGEN SUPPLY F 3 a/f .v

lg 37 88 INVENTOR.

REUBEN FLANAGAN GRAY May 14, 1963 R. F. GRAY l 3,089,482

APPARATUS FOR CONTROLLING THE VOLUME)` OF AIR AND THE DISTRIBUTION OF BLOOD IN THE BODY Filed May 28, 1959 3 Sheets-Sheet 5 INVENTOR. REUBEN FLANAGAN GRAY `Reuben Flanagan Gray,

vto the head so as to United States Patent esatta `Patented May 14, 1963 thee APPARATUS FOR F AIR AND THE DHSTRIBUTION 0F BLOOD IN THE RUDY Levittown, Pa., assigner to the United States of America as represented by the Secretary of the Navy Filed May 23, 1959, Ser. No. 816,650 12 Claims. (Cl. 12S-1) (Granted under Title 3S, U.S. Code (1952), sec. 266) The invention described herein may beV manufactured by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to apparatus for increasing human tolerance to accelerative Iforces and more particularly to apparatus for increasing human tolerance to accelerative forces by controlling the volume of air and the distribution of blood in the body.

Various types of anti-blackout instrumentalities existing in the prior art are instrumental in mitigating with varying degrees of facility the depletion of .blood ilow prevent anemia of the retina, or blackout during periods in which the subject of pilot is being subjected to centrifugal accelerations, such as those experienced in the dive maneuvers of an aircraft. While such apparatus is satisfactory in applications wherein the acceleration forces are of a relatively low order, the devices of the prior art are inadequate in preventing blackout, unconsciousness, or serious physical injury to the subject, when the acceleration forces bearing on the vascular system are of the order of hundreds of Gs, such as those contemporarily entertained in space work, a unit of G being herein denoted as that of normal gravity. In laboratory experiments conducted with animals which died from effects of centrifugation, it was observed on autopsy that failure of the respiratory center Awas a factor instrumental in the deaths of the animals involved in the experiment, as evidenced by the accumulation of blood in the base `of the lungs. In addition, hemorrhaging of both heart and lung tissue was observed.

Apropos of the noted evidentiary factors and the inadequacies of the devices of the prior art to render satisfactory protection, the instant invention assures the protection of a subject against the adverse effects of relatively large acceleration forces. The premise upon which the instant invention is `based resides in the use of a closed constant volume container or capsule, which is iilled with an incompressible iuid medium, such as water, having a density approximating that of blood, in which the subject is completely submerged, together with provisions for aiding circulation and respiration yof the subject during periods of accelerative stress. The use of water in a closed constant volume container or capsule counterbalances at every point the pressure exerted by the body such that distortion of body tissues under ac- CONTROLLING THE VOLUlViE celerative stresses is greatly minimized, while the mechal 'cally supplies pressurized air between preselected limits to the lungs of the subject, so that :the pressure supplied to the lungs offsets the hydrostatic pressure of the vascular system. In this manner, the equalization of pressures results in little tendency for accumulation of blood in the lung sacs. While blood circulation in the body is also improved by this means, a positive mechanism for aiding circulation is provided in the instant invention by directly varying the pressure of the water at the circulatory rate. Thus, in the manner summarily set forth, the apparatus of the instant invention provides protection for a subject against physical injury or disability when exposed to G forces of the magnitude such as those enof apparatus for the protection of a subject against the adverse effects of high G levels.

Another object is to provide for the protection of a subject by minimizing the intrusion of blood into the gas containing spaces of the body due to the 4action of accelerative forces.

A further object of the invention is the provision of apparatus yfor forcing circulation notwithstanding collapse of yblood vessels in the vascular system due to the action of acceleration.

Still another object is to provide for the respiration of a subject in a closed constant volume fluid lilled container..

A further object of the invention is to provide means for resuscitating a subject from apparent death or unconsciousness by forced respiration or forced circulation,

.or both simultaneously.

. ject.

FIG. 3 is a simplified schematic diagram of the respiratory apparatus necessary for providing a reciprocating pressure to the lungs of a subject housed in the pressure cell of the instant invention.

FIG. 4 is a schematic diagram of the electrical circuits necessary for controlling various functions relating vto the pressure cell, and

FIG. 5 is a partial sectional view of an alternate embodiment, illustrating the use of a molded compositional medium for supporting and minimizing distortion of the body during periods of accelerative stress.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a pressure cell shaped generally to accommodate a subject in the sitting position. The pressure cell is made preferably from a light weight material, such as aluminum, or the like, and is constructed in two sections, an upper pressure cell member 11 and a lower pressure cell member 12, joined at Itlanges '14 and 15. The structure ofthe pressure cell is characterized as rigid and non-expansible. Dump valve 16 is normally electrically opera-ble to provide Afor selective control of an opening between the interior of the cell and exit 17 in elbow 20, which opens to atmosphere. Provision is made for the manual operation of dump valve 16 by the handle 13, such as may be desirable during experimental laboratory operation. Electrically operated valve 19 controls at the command of the subject the tiow of water from a suitably pressurized source via conduit 21 to the interior of the pressure cell. Portholes with porthole covers 22 therefor 4are provided in the upper pressure cell member 111, as illustrated, for convenient access during experimental laboratory operation. A tightening handle 23 is supplied for sealing each of the portholes in a conventional manner. A portion of the respiratory tube 24 is shown in upper pressure cell member 11. In a comparable manner, circulatory tube 48 is coupled to the pressure cell by a conventional threadable member 40. Visual access for the subject is provided by a transparent lens 26, which is retained in position, as illustrated, by retainer 27. Bleed valve 28 is electrically controlled and functions to bleed ott entrapped air within the cell during the filling operation. A standpipe 31 is supplied for modifying the hydrostatic pressure on the subject during the tilling operation.

FIG. 2 presents in greater particularity the structure of the pressure cell shown in FIG. l, in addition to apparatus `for supplementing the circulatory function of the subject during periods of adverse accelerations. Conduit 32 connects the lower half member of the pressure cell to dump valve 16. A plurality of clasp type latches 33 are peripherally disposed about gasket 13 providing in conventional manner the pressure necessary for sealing the upper half member 11 with the lower half member 12. A waterproof control box 34, connected by means of a multiconductor cable 35 to the terminal box 36, enables the subject to control remotely the operation of the pressure cell. The standpipe valve 37, connected to standpipe 31 and having an optionally manually operated valve handle 38, is normally electrically actuated by the subject to control the level of water in standpipe 31, and thereby the hydrostatic pressure within the cell. A conduit 39 connects the interior of the pressure cell to the standpipe. A restraining member 41 is employed for supporting with the aid of conventional fastening means standpipe 31 to the upper half of the pressure cell -11. Handle 23 is threadably engaged with bracket 61, assuring with the aid of a suitable gasket for the watertight integrity of the pressure cell.

Deformation of the chest due to hydrostatic pressure acting on the lower part of the body during periods of positive acceleration, i.e., accelerative forces acting downwardly in the view of FIG. 2 as in normal gravity, is minimized by the use of a rigid vest or cuirass 42, constructed in two parts from a light weight rigid material such as, for example, aluminum or the like. The cuirass is fabricated to substantially fit the contour of the chest, and the right and left portions thereof are joined at the front and back of the cuirass by conventional fastening means 43. While `the use of such mechanism may be dispensed with when the subject is to be exposed to relatively low G levels, much higher G tolerance is possible by its use. A mask 44 covering the portion of the face including the nose and mouth is provided for supplying pressurized air to the subject. Conventional webbing supports the mask against the subjects face, providing at the peripheral edge contiguous with the face an airtight seal. The respiratory tube 24 connects to the mask, as illustrated in FIG. 2. If desired, the subject may use corrective lenses, not illustrated, to compensate or the refractive index of the water in which he is immersed, so that clear vision may be provided through the transparent glass 26.

The apparatus for aiding the circulatory function of the subject is generally designated in FIG. 2 by numeral 46. A pump 47 is schematically illustrated to supply a reciprocating pressure via the hose or conduit 48 to the interior of the pressure cell. Arm 49 is driven by a stud 51 fixedly mounted on wheel 52. The latter is shown by the dotted line notation to be driven by a direct current motor 53, having a eld winding which is selectively energized from either the energy source 54, or direct current amplifier 55. Switch 58 energizes motor 53, except for the iield winding. With contacts 56a closed in the position illustrated by the action of armature 56h, rheostat 57 is adjusted so that pump 47 is operating at a predetermined xed rate comparable with the period of the subjects heart pulsations. In the alternate position, closing of contacts 56C with armature 5611 energizes the eld of motor 53 from the output of D.C.

amplitier S5, the input for which is obtained from a smoothing network 62, consisting of a conventional low pass filter having appropriate electrical RLC elements. The input to network 62 is an electrocardiogram voltage (E.K.G.), developed across a pair of suitably insulated electrodes, not illustrated, which are placed at selected points on the body of the subject. Network 62 is therefore operable to convert the spikelike voltage pulsations characterizing an electrocardiogram voltage into a D.C. potential level proportional to the frequency of the pulsations. Accordingly, motor 53 rotates at a rate corresponding to the frequency of the voltage pulsations appearing at the input of the smoothing network. Thus, in the manner described, pump 47 operates at either a predetermined iixed speed depending upon the setting of control 57, or at an automatic rate coincident with the circulatory period of the subject.

The respiratory apparatus for cyclically providing a regulated llow of pressurized air to the subject is shown in FIG. 3. Motor 63 is connected to a suitable source of D C. excitation 64, except for its field windings, which are connected to selectively receive the output of either D.C. supply 65, or D.C. amplier 66. In the position illustrated, the yarmature 67b completes the circuit of the eld winding of motor 63 to the D.C. supply 65 by closing contacts 67a, so that motor 63 rotates at a fixed rate of speed determined by the setting of rheostat 69. In the alternate position, the closing of armature 67h with contacts 67C completes the circuit of the field winding to DC. amplifier 66. The level of output voltage from amplifier 66 is such as to cause motor 63 to rotate at a speed consonant `with the oxygen demand requirements of the subject. The oximeter 73 is a translation device which functions to produce a D.C. output voltage corresponding to the CO2 content in the blood stream of the subject. =In its simplest form, such device may be a photoelectric cell which is responsive to changes in the color of the auricles, the latter being interposed between a point source of light and a photoelectric cell. Thus, in the manner set forth, the speed of motor 63 may be selectively controlled at either a ixed predetermined rate according to the setting of rheostat 69 or at an automatic rate of rotation consonant with the oxygen demand requirements of the subject.

Motor 63 in FIG. 3 drives a worm gear 75 which is meshed with a gear 76. Shaft 77 is keyed to gear 76, as well as to the eccentric cams 78 and 79. The rotation of cam 73 actuates microswitch 81 which energizes the buzzer and signal light circuit from the battery or electrical power source 7G. The signal circuit including buzzer 60 and lamp 71 is employed in the instant invention to signal to the subject when exhalation and inhalation is to occur, since proper phase relationship between the cyclic flow of pressurized air and the breathing of the subject is essential for satisfactory operation of the instant invention. The surface of cam 79 is in contact with push rod 30, which moves in a reciprocating manner. Numeral 50 designates a source of pressurized air or oxygen. A manually operated pressure regulator 82 regulates the upper pressure limit of the oxygen at the entrance to valve 83 to be at some nominal value such as, for example, l() p.s.i. above atmospheric pressure. Valve 83 provides for a reciprocating pressure to be developed at its outlet, such that in conduit 84 the flow of pressurized air is regulated between predetermined upper and lower pressure limits of lO-6 p.s.i., respectively, above atmospheric pressure, which pressure range should be understood as merely illustrative. The lower pressure limit is a direct function of acceleration, that is to say, with higher contemplated accelerations, the higher the lower pressure limit. A manually Operated exhaust choke member 8S permits adjustment of the lower pressure limit. A corresponding increase in the upper pressure limit should be understood. Conduit 84 connects at its lower extremity into an electrically operated three way valve 86 which is operable to selectively deliver to the respiratory tube 24, either the cyclically pressurized air of conduit 84 or the ambient air at atmospheric pressure entering the lower open end of tube 87. It should be understood that the lower end of tube 87 may be connected to a source of air other than ambientA air. Interposed in respiratory tube 24 is a pressure responsive safety switch 88, which closes at atmospheric pressure and opens when the pressure in tube 24 exceeds a predetermined level.

Referring next to FIG. 4, there is shown a simplied electrical schematic diagram of the various control circuits necessary for the operation of the instant invention. Switches 90 through 96 are located on the control box 34, and control the energization of relays or valves, the coils or solenoids for which are shown with a prefix K in FIG. 4. It should be further understood that the numeral following the prelix represents the element in which the relay coil or solenoid is a part thereof. For instance, the bleed valve On-Olf switch 92 controls the opening of bleed Valve 28' illustrated in IFIGS. 1 and -2 by completing the circuit of solenoid K28 through the source 89. Simultaneously with the actuation of bleed valve 218, the solenoid KZS also opens the contacts designated in FIG. 4 as KZSa and closes K28b. These contacts are provided for the purpose of safety interlocking the various circuits so that energization of the various mechanisms of the instant invention is performed in proper sequence. Thus, proceeding from left to right in FIG. 4, the water On-Olf switch 90 controls the flow of water through valve 19 by energizing relay coil K19, providing contacts K280i and K376i are closed, as illustrated in the deenergized state of the bleed valve solenoid K28 and standpipe valve solenoid B137, respectively. The dump On-Ofr switch 9,1, which controls the efflux of water from the pressure cell, opens valve d6 by energizing the dump solenoid K16 only if contacts 88a are closed when the pressure in the respiratory tube 28 is at atmospheric pressure. The control circuit for the bleed valve 28 has already been set forth. The closing of standpipe On-OI switch 93 causes the standpipe valve 37 in FIG. 2 to close and its associated contact K'S'a in the water inlet circuit opens, preventing further entrance of water. Switch 94 is the pressure-ambient selector switch, which is depicted in the ambient or open position. -In the open position, the subject within the pressure cell is breathing arnbient air through valve 86. If bleed valve 28 and standpipe valve 37 are closed, contacts K28b and K37b will be closed, allowing the subject to switch to pressurized air by closing switch 94 to the closed or pressure position. Energization of solenoid K86 will thus actuate valve 86 shown in FIG. 3 to the pressure position. In the normally open position of the E.K.G.normal switch 95, contacts 56a in lLFIG. 2 are closed by armature 5612, as illustrated, allowing motor 513 to rotate at a fixed rate of rotation providing switch S8 -is closed. In the closed position lof switch 95, the subjects circulatory system is vbeing supplemented at an automatic rate, since contzzts 56e are closed by armature 56b in FIG. 2 to the alternate position. In a similar manner, the closing of the oximeter-normal switch 96 in FIG. 4 energizes the sole- 'noid 146,7 or relay 167, causing the armature 67b in FIG.

3 to close with contacts 67e.

Referring next to the showing in FIG.V 5, there is illustrated an alternate capsular construction in which the Vbody surface of the subject except for a portion of the countenance is in substantial contact at every point with a light weight supporting compositional medium having preferably non-elastic characteristics, such as polyurethane foam, plastic, or the like, designated by numeral 97. By so enveloping the subject, minimizing the lstress concentrations and `body distortion during periods in which the subject is undergoing acceleration, the tendency for edematous effects are greatly reduced. The external shell 98 of the capsule is of a material such as vthis closure.

is filled with water, or an isotonic iluid, such as aluminum, impregnated iibre glass, or the like, and is Yconstructedinto two parts, having continuous anges 99 and 101. To afford convenient access, the structure of vthe capsular pressure cell is provided with hinges, not illustrated in the view of FIG. 5, which facilitate closing the capsule. An electrically actuated electromagnetic latch 102 is provided for securing the two sections after closing, and has provisions for being manually operated by the subject from inside the capsule. A control box 10'3 is provided, as before. As in the embodiment of FIG. 1, provision is made for supplying pressurized air to the subject. For this purpose, a special mask is provided suchthat a complete closure is formed over the portion of the face which includes the mouth and eyes. An inflatable seal y104 having an inlet Valve 11d and a rigid portion 105 form the outer peripheral surface of VFilled Ear Mutis, filed January 28, 1959, now Patent No. 2,933,086. Straps 109 support 4iirmly the mask against the face of the subject to thus insure integrity of sealing. It should be understood that while the embodiment illustrated in FIG. 5 is substantially lighter in weight than theembodiment depicted in either FIG. 1 or FIG. 2 due to the use of the light weight plastic supporting medium for enveloping the subject, Water may be used to ll possible voids existing between the surface of the subjects body and the supporting medium.

Preliminary to being subjected to accelerative stresses, the pressure cell of the instant invention must. rst be iilledV with water. This phase of the operation is best described inV connection with the showings in FIGS. 2,

V3 and 4. The subject is assumed to be in a position illustrated in FIG. 2 with the cuirass 42 in place and the mask 44 properly secured. Porthole covers 22 and fasteners 33 are checked to assure that the pressure cell is -sealed. Switches through -96 are all in open position.,

as illustrated in FIG. 4. Bleed Valve 28 and the standpipe valve 37 are therefore initially opened. Dump valve 16 is closed. The circulatory apparatus 46 illustrated in FIG. 2 is initially deenergized by switch 5'8 being in the open position.

The respiratory apparatus in FIG. 3 is operating, but since the pressure-ambient selector switch 94 is in the ambient or open position, ambient air is being supplied to the subject. Thus, the subject is using'natural `breathing at this time. Water is admitted to the pressure cell Iby closing the water On-Off switch 90, the water rising until the subject is completely immersed, and

Yis llowing from bleed valve 28. In standpipe 31, the

water rises to the level of -bleed valve 28. When the flow from Valve 218 is constant, indicating that the entrapped air within the pressure cell has been expelled, the Water On-Off switch 90l is opened and the bleed valve 28 is closed by closing switch 92. To assure a comfortable hydrostatic pressure for the subject when ambient air is being supplied, dump valve 16 is actuated by closing the dump switch 91, premitting the level of the water in the standpipe to ybe lowered until approximately level Ywith the mouth or ears of the subject, at which level 'dump valve 16 is closed. At this point, the apparatus is in readiness for exposure to acceleration. Since no constricting `forces bear on the body at this time, the level of the water in standpipe 37 fluctuates in response to the subjects natural breathing.

Whenaccelerative stresses are expected, the standpipe Valve`f37 is closed by closing switch 93. The pressure cell is now completely closed, the subject being incap- A second closure is provided for the area able of breathing in the normal sense, since the body is immersed in a nonexpansive container in an incompressible liquid. The pressure-ambient switch 94 is now ready to be closed to the pressure position. Upon closing of switch 94, valve 86 is actuated, admitting pressurized air or oxygen to the respiratory tube 24. While the chest or limbs are thus maintained stationary, the pressurized air, which cyclically recurs between the illustrative upper and lower pressure limits previously set forth, is supplied to the lungs of the subject, achieving in this manner atrificial respiration. In order to obtain a degree of coordination between the subjects breathing and the respiratory apparatus illustrated in FIG. 3, the sounding of buzzer 6() concurrent with the illumination of bulb 71 as microswitch 81 is actuated in response to cam 7S, signals to the subject that inhalation is about to commence. Interruption of the buzzer and light cil'- cuit signals to the subject that the exhalation cycle is to begin. Thus, by cyclically supplying pressurized ail to the lungs, the tendency for blood to accumulate in the lungs as a function of increased hydrostatic pressure in the vascular system of the body during periods of positive acceleration is `greatly reduced. In addition, the circulatory function of the heart is made easier due to the action of the pressurization mechanism. Accordingly, a premise upon which the invention is based resides in the fact that the hydrostatic pressure of the bodys internal fluids is directly offset -by the pressurization supplied to the lungs. While the description of the operation of the instant invention delineated thus far has been made in connection with the respiratory apparatus of FIG. 3 functioning at a fixed rate, respiration, of course, may be selected at the automatic rate responsive to oximeter 74, by closing the oximeter-normal switch 96 to the oximeter position. In this manner, the respiratory apparatus of FIG. 3 has a period corresponding to oxygen demand requrements of the subject. It should further be noted with respect to the showing in FIG. 2, that the hydrostatic pressure of the water under the influence of positive acceleration acts to contract the abdomen and to expand the chest, while still maintaining the volume of the body constant. It is the purpose of cuirass 42 to minimize such distortion during periods of acceleration.

While the apparatus embracing the pressurized respiratory concept of the instant invention greatly increases human tolerance to accelerative forces, the circulatory apparatus 46 depicated in FIG. 2 may be used to supplement the function of the heart, to thus minimize depletion of blood at the head, and in this manner, further extend human tolerance. Since the body is confined in a non-expandable container in an incompressible fiuid, the reciprocating pump 47 acts directly on the circulatory system of the body. The period of pump 47 should be understood as being a fractional part of the respiratory cycle, and in the E.K.G. position of switch 95, motor 53 runs at a rate which is conincident with the frequency of the subjects heart pulsations. Thus, during periods of accelerative stress, the circulatory system of the body may be selectively aided or supplemented at the command of the subject by closing both switch 58 in FIG. 2 and switch 95 in FIG. 4.

Hence, the invention as described is instrumental in greatly increasing human tolerance to G forces, by providing forced respiration or forced circulation, or both simultaneously. In the same manner that the invention augments the natural functions of the respiratory and circulatory organs of a subject when impaired by high acceleration forces, the invention can be used for resuscitating a subject from apparent death or unconsciousness when his natural functions are incapable of restoring normal respiration and circulation. By holding the chest stationary, pressurization of the lungs is provided such that the instant invention is instrumental in stopping the intrusion of blood into the lungs and the gas containing spaces of the body due to the action of acceleration. In addition, the instant invention promotes blood circulation despite collapse of blood vessels. Furthermore, while the instant invention is particularly applicable in the field of aviation medicine, it is not restricted as such, and may be used as a general resuscitation apparatus.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

What is claimed is:

l. Pressure breathing apparatus comprising: an enclosed rigid wall container including a head portion shaped to house a subject, an incompressible liquid having a density approximating that of the subjects blood filling the space in said container unoccupied by the subject for completely immersing the subject therein, and respiratory means extending into said head portion and adapted for supplying to the immersed subject pressurized air cyclically varying between preselected limits above ambient atmospheric pressure.

2. Pressure breathing apparatus comprising: an enclosed container including a head portion shaped to house a subject, an incompressible liquid having a density approximating that of the subjects blood filling the space in said container unoccupied by the subject for completely immersing the subject therein, respiratory means extending into said head portion and adapted for supplying to the immersed subject pressurized air cyclically varying between preselected limits above ambient atmospheric pressure, and circulatory means coupled to said container and operable to cyclically vary the pressure of said liquid for aiding blood circulation of the immersed subject.

3. Pressure breathing apparatus comprising: an enclosed rigid wall container including a head portion shaped `to house a subject, an incompressible fluid having a density approximating that of the subjects blood filling the space in said container unoccupied by the Subject for completely immersing the subject therein, said container being constructed into at least two sections, each section having a continuous flange in juxtaposition with the other flange, securing means including a resilient gasket interposed between each of the flanges for providing sealing of said pressure breathing apparatus, a fiuid supply source, inlet means communicatively connected between said container and said source and including a valve for controlling the admission of said fluid, bleeder means communicatively connected to said container for closing off said fiuid in said container from atmospheric pressure, outlet means communicatively connected to said container and including a valve for controlling the discharge of said fluid, and respiratory means extending into said head portion and including a mask formed to seal around the mouth and nose of subject to provide him with pressurized air cyclically varying between preselected limits above ambient atmospheric pressure.

4. Pressure breathing apparatus comprising: an enclosed rigid wall container including a head portion shaped to house a subject, an incompressible fiuid having a density approximating that of the subjects blood filling the space in said container unoccupied by the subject for completely immersing the subject therein, said container being constructed into at least two sections, each section having a continuous fiange in juxtaposition with the other flange, securing means including a resilient gasket interposed between each of the anges for providing sealing of said pressure breathing apparatus, a fiuid supply source, inlet means communicatively connected between said container and said source and including a valve for controlling the admission of said fiuid, bleeder means communicatively connected to said container and selectively operable to expel entrappcd air from said container, a stand pipe communicatively connected to said container and including a valve for controlling the discharge of Said ansa-rsa fluid, and respiratory means extending into said head portion and including a mask formed to seal around the mouth and nose of the subject to provide him with pressurized air cyclically varying between preselected limits above ambient atmospheric pressure.

5. Pressure breathing apparatus comprising: an enclosed rigid wall container including a head portion shaped to house a subject, an incompressible iluid having a density approximating that of the subjects blood tilling the space in said container unoccupied by the subject for completely immersing the subject therein, said container being constructed into at least two sections, each section having a continuous flange in juxtaposition with the other flange, securing means including a resilient gasket interposed between each of the flanges for providing sealing of said pressure breathing apparatus, an electrical control box means operably disposed for manual actuation by the immersed subject, a source of iluid pressure, inlet means communcatively connected between said container and said source and including a valve for controlling the admission of said fluid, bleeder means communicatively connected to said container and selectively operable to expel entrapped air from said container, a stand pipe communicatively connected to said container and including a valve for closing 01T said uid in said container from said stand pipe, outlet means communicatively connected to said container and includ-ing a valve for controlling the discharge of said fluid, oximeter means for-med to be operatively connected to the blood stream of the immersed subject and producing an electrical signal corresponding to his oxygen requirements, and respiratory means extending into said head portion and responsive to said signal including a mask formed to seal around the mouth and nose of the subject to provide him with pressurized air cyclically varying between preselected limits above ambient atmospheric pressure at a rate corresponding to the oxygen requirements.

I6. Pressure breathing apparatus comprising: an enclosed rigid wall container including a head portion shaped to house a subject, an incompressible luid having a density approximating that of the subjects blood lling the space in said container unoccupied by the subject for completely immersing the subject therein, said container being constructed into at least two sections, each section having a continuous ange in juxtaposition with the other iiange, securing means including a resilient gasket interposed between each of the flanges for providing sealing of said pressure breathing apparatus, an electrical control box means operably disposed for manual actuation by the immersed subject, a source of uid, Iinlet means communicatively connected between said container and lsaid source and including a valve for controlling the admission of said fluid, bleeder means communicatively connected to said container and selectively operable to expel entrapped air from said container, a stand pipe communicatively connected to Said container and including a valve operable to close off said fluid in said container from said stand pipe, outlet means communicatively connected to said container and including a valve for controlling the discharge of said Huid, respiratory means extending into said head portion and including a mask formed to seal around the mouth and nose of the subject to provide him with pressurized air cyclically varying between preselected limits above ambient atmospheric pressure, and circulatory means coupled to said container for cyclically varying the pressure of said fluid.

7. The pressure breathing apparatus of claim 6 in which said circulatory means for cyclically varying the pressure of said uid comprises a pump, a motor means drivingly connected to said pump, and control means extending into said container and formed to be controlled by the immersed subject, and a source of excitation yoperatively connected to said motor.

8. Pressure breathing apparatus comprising: an enclosed rigid wall container including a head portion shaped to house a subject, an incompressible lluid having a density approximating that of the subjects blood iilling the space in said container unoccupied by the subject for completely immersing the subject therein, said container being constructed into at least two sections, each section having a continuous flange in juxtaposition with the other ange, securing means including a resilient gasket interposed between each of the flanges for provining sealing of said pressure breathing apparatus, an electrical control box means operably disposed for manual actuation by the immersed subject, a source of pressurized uid, inlet means communicatively connected between said container and said source and including a valve for controlling the admission of said Huid, bleeder means communicatively connected to said container and selectively operable to expel entrapped air within said container, a stand pipe communicatively connected to said container and including a valve to close oit said uid in said container from said stand pipe, outlet means communicatively connected to said container and including a valve for controlling the discharge of said duid, respiratory means extending into said head portion and including a mask formed to seal around the mouth and nose Iof the lsubject to provide him with pressurized air cyclically varying between preselected limits above ambient atmospheric pressure, electrocardiograph means formed to be operatively connected to the subject and producing an electric signal corresponding to his heartbeat, and circulatory means coupled to said container operable to cyclically vary the pressure of said Huid in response to said signal at a rate corresponding to his heartbeat, thereby aiding blood circulation of the immersed subject.

9. Pressure breathing apparatus comprising, an enclosed rigid wall container including a head portion shaped to house a subject, an incompressible iluid having a density approximating that of the subjects blood lling the space in said container unoccupied bythe subject for completely immersing the subject therein, said container being constructed into at least two sections, each section having a continuous ilange in juxtaposition with the `other ilange, securing means including a resilient gasket interposed between each of the ilanges for providing sealing of said pressure breathing apparatus, an electrical control box means disposed for manual actuation by the immersed subject, a source of pressurized duid, inlet means communicatively connected between said container and said source and including a valve for controlling the admission of said fluid, bleeder means communicatively connected to said container and selectively operable to expel entrapped air from said container, a standpipe communicatively connected to said container and including a valve for closing 01T said fluid in said container from said stand pipe, outlet means communicatively connected to said container and including a valve for controlling the discharge of said fluid, oximeter means formed to be operatively connected to the blood stream of the immersed subject and producing an electrical signal corresponding to his oxygen requirements, respiratory means extending into said head portion and responsive to said signal and including a mask formed to seal around the mouth and nose of the subject to provide him with pressurized air cyclically varying between preselected limits of ambient atmospheric pressure, electrocardiograph means formed to be operatively connected to the subject and producing an electric signal corresponding to his heartbeat, and circulatory means coupled to said container operable to cyclically vary the pressure of said iiuid in response to said signal at a rate corresponding to his heartbeat, thereby aiding blood circulation of the immersed subject.

10. Pressure breathing apparatus comprising: an enclosed rigid wall container including a head portion shaped to house a subject therein, incompressible supporting medium bounded by the inner surface of said container and contoured ito substantially envelope the subject in a contiguous relation within said container, and respiratory means extending into said head portion and including a mask formed to seal around the mouth and nose of the subject for supplying to him pressurized air cyclically varying between preselected limits above ambient atmospheric pressure.

11. Pressure breathing apparatus comprising: an enclosed rigid wall container including a head portion shaped to house a subject, said container being constructed into at least two sections, each section having a continuous iiange in juxtaposition with the other flange, latching means mounted on said iianges for securing said pressure breathing apparatus, incompressible supporting means being Xed to the inner surface of said container contoured to substantially envelope the subject therein in a contiguous relation within `said container, and respiratory means extending into said head portion and including a mask formed to seal around `the mouth and nose of the subject for supplying to him pressurized air cyclically varying between preselected limits above ambient atmospheric pressure.

12. The pressure breathing apparatus of claim 11 in which the supporting medium is a polyurethane foam 5 product.

References Cited in the le of this patent UNITED STATES PATENTS 

1. PRESSURE BREATHING APPARATUS COMPRISING: AN ENCLOSED RIGID WALL CONTAINER INCLUDING A HEAD PORTION SHAPED TO HOUSE A SUBJECT, AN INCOMPRESSIBLE LIQUID HAVING A DENSITY APPROXIMATING THAT OF THE SUBJECT''S BLOOD FILLING THE SPACE IN SAID CONTAINER UNOCCUPIED BY THE SUBJECT FOR COMPLETELY IMMERSING THE SUBJECT THEREIN, AND RESPIRATORY MEANS EXTENDING INTO SAID HEAD PORTION AND ADAPTED FOR SUPPLYING TO THE IMMERSED SUBJECT PRESSURED AIR CYCLICALLY VARYING BETWEEN PRESELECTED LIMITS ABOVE AMBIENT ATMOSPHERIC PRESSURE. 